[RekiM]

I would also like this feature. As a workaround I've been using MPV as an external player. With MPV you can speed up the video and it will automatically adjust the audio pitch/tempo.

Here's some basic instructions for Windows:
- You can downlad MPV from http://mpv.io/
- The Windows binary downloads are here: http://mpv.srsfckn.biz
- Extract to "C:\Program Files\MPV\" (or whatever path you want)
- Create a file called "playercorefactory.xml" in your "UserData" folder.
- Add the following to playercorefactory.xml:

Code:

<playercorefactory>
<players>
   <player name="MPV Fastplay" type="ExternalPlayer" audio="false" video="true">
     <filename>C:\Program Files\MPV\mpv.exe</filename>
     <args>"{1}" --speed=1.33 --fs</args>
     <hidexbmc>false</hidexbmc>
     <hideconsole>false</hideconsole>
     <warpcursor>none</warpcursor>
   </player>
</players>
</playercorefactory>

I set the default speed to 1.33x, but you can use the [ and ] keys to increase and decrease the speed during playback.